The field of this invention relates to high surface area silver olefin oxide catalysts with orderly distribution of pore size, to high surface area carbon-like polymers containing silver useful as catalysts and bactericides, to high surface area carbon-like adsorbents or predetermined structure, and to the process for producing these novel silver catalysts, bactericides, and carbon adsorbents.
The use of silver as a catalyst for the oxidation of ethylene to ethylene oxide is well known, as is also the preparation of silver catalysts by the thermal decomposition of aliphatic silver salts, in particular silver oxalate but also silver formate and silver acetate. There has also been interest recently in silver catalysts with high surface areas for the oxidizing of olefins utilizing silver ketenide as an intermediate. An inherent problem with silver ketenide is that its carbon-silver bonds are often unstable, so that silver ketenide can and does decompose explosively. A search for a more stable silver catalyst intermediate led to the pyrolyzed silver salts and silver catalysts of this invention derived from aromatic and heterocyclic compounds.
The biocidal effects of silver in its free form and in the form of its salts are well-known. A controlled rate of release of silver ions into the bacteria-containing media is desirable because of the wellknown low level of silver ion which causes a biocidal effect, less than 10 parts per million in water being required. It has been found that the high surface area and ordered structures of the carbon-like polymers which contain silver produce conveniently the controlled release of the silver ions into a bacteria-containing media.
The adsorptive power of activated carbon is well-known to be a resultant of several factors among which are pore size, total area available, and structure. The novel carbon-like polymers of this invention have high surface area and are of predetermined structure with consequent increased adsorption rate.